Often, a substrate such as a turbine shaft of a gas turbine engine must be prepared before it can be cold sprayed so that the material will adhere thereto. A common preparation technique is known as abrasive or grit blasting, which consists of applying an abrasive material against the substrate at a relatively high pressure so as to smooth the substrate.
One of the disadvantages of grit blasting is that the abrasive material can become embedded in the substrate, thereby contaminating the substrate, which is undesirable for substrates which require a certain material purity. Contamination of the substrate can also result because the abrasive material used is different from the coating material.
Accordingly, there exists a need for a method for applying a coating to a substrate.